Locking mechanism



March 24, 1964 M. A. ROBINSON LOCKING MECHANISM Filed Sept. 10, 1962IIIIIIIIIIIIIIIII INV EN TOR. flme/rr A. 206/460 United States Patent3,125,873 LOCKING MECHANEM Merritt A. Robinson, Marin County, alif.,assignor t0 Kimball Manufacturing Qorporation, San Rafael, Galifi, acorporation of California Filed Sept. 10, 1%2, Ser. No. 222,6% 9 Claims.(Cl. 70-63) This invention relates to a locking mechanism and morespecifically to a locking mechanism having flexible tumbler portions anddesigned for minimum security purposes.

The present invention finds particular utility in household containerssuch as boxes or cabinets wherein medicines, household chemicals andother dangerous items are to be kept away from children. For suchpurposes, a lock is required which will keep the container securelyclosed but which will enable the container to be opened easily whendesired. Since small children are equipped with but limited coordinationand mechanical knowledge, it is not necessary that a lock be undulycomplicated to perform the necessary locking function. It is the primaryobject of the invention to provide such a lock.

A further object of the invention is to provide an inexpensive lockingmechanism which can be molded integrally with a plastic container.

Although the present invention finds utfiity in connection withhousehold containers, it is to be realized that the use is notnecessarily limited thereto. Instead, the present invention haswidespread application where it is desired to provide an inexpensivelock for fastening two members together.

Other objects and advantages will become apparent in the course of thefollowing detailed description.

In the drawings which form a part of this application and in which likereference numerals are used to indicate like parts throughout the same,

FIG. 1 is a perspective view of a container and key embodying theprinciples of this invention;

FIG. 2 is a plan view in enlarged scale of the locking mechanism of FIG.1;

FIG. 3 is a sectional view taken on lines 3-3 of FIG. 2;

' FIG. 4 is a sectional view taken on lines 4-4 of FIG. 2, showing themechanism in locked position;

FIG. 5 is a side elevational view of the key utilized in the presentinvention;

FIG. 6 is an end elevational view of the key of FIG. 5;

FIG. 7 is a sectional view, similar to FIG. 4, showing the key beingutilized to move the locking tumblers to unlocked position; and

FIG. 8 is a plan view of the showing of FIG. 7, illustrating the partsin their unlocked position. 7

Referring now to the drawings wherein is illustrated a preferredembodiment of the invention, reference numeral 10 refers generally tothe container which comprises a lid member 11 and a body member 12 whichlid and body members are joined together by hinges such as are indicatedgenerally at 13. Also fllustrated in FIG. 1, is a key 14 shown ingeneral positionto cooperate with the "ice are two aligning apertures orslots 25 and 26. As is noted, the aligning apertures 25 and 26 extendinto the recess 15 and intersect the locking apertures 16 and 18.

The container body 12, which is preferably an injection molding ofpolypropylene, has provided therein as an integral part thereof threetumblers 27, 28 and 2%, which are integrally molded with an internalpartition 30 of the body 12. As is shown in FIG. 4, the tumbler member28 has a reduced-thickness neck 31 which enables the tumbler member toflex slightly to the left and right as viewed in FIG. 4. The tumbler 28has the upper portion 28a thereof extending through the locking aperture17 and when the tumbler member 28 is in its unfiexed position shown inFIG. 4 the locking shoulder 32 formed on the tumbler portion 28a hooksover and engages the locking shoulder 21 of the locking aperture toprevent the lid and body from being opened relative to each other.

It will also be noted that the portion 28a of the locking tumbler 28which projects through the locking aperture is completely within therecess 15 of the lid and does not extend thereabove. This enclosure ofthe tumblers in the recess makes it very difiicult to open the lidwithout the use of key 14. The over-all width of the tumbler 28, fromthe locking shoulder 32 to the opposite side thereof, is less than thedistance betwen the opposite shoulders 21 and 22 of the lockingaperture.

In like fashion, the tumbler members 27 and 29 extend through thelocking apertures 1'5 and 18, respectively, and the tumblers areprovided with locking shoulders 33 and 34, respectively, which engagethe locking shoulders 19 and 23 of the apertures 16 and 13 when thetumblers are untiexed.

The tumbler member 28 has a recess 36 formed into the end thereof whichis provided with a cam surface 37 for use in unlocking the tumbler, aswill be described hereinafter. Similarly, tumblers 27 and 29 areprovided with recesses 38 and 39 into the ends thereof, which recessesare provided with unlocking cam surfaces 4-9 and '41, respectively.

FIG. 5 illustrates the key 14 utilized for unlocking the tumblers of theinvention; As is noted, key 14 is provided with five depending prongs,the outermost being alignment prongs 42 and 43 for cooperation with thealignment apertures 25 and 26 of the lid. The intermediate unlockingprongs 44, 45 and 46 are designed to cooperate with the recesses 38, 36and 39 of the tumblers, respectively.

To open the container 10, the alignment prongs 42 and 43 of the key areinserted into the alignment apertures 25 and 26 of the lid. As the keyis moved downwardly, the unlocking prongs 44, 45 arid 46 enter thelocking mechanism of the container 10 to unlock the lid from the body12. 7

As best seen in FIGS. 2, 3 and 4, the lid 11 is provided with a recess15 in the top thereof. Three generally rec tangular locking apertures16, 1'7 and 13 are formed through the bottom of the lid recess. Lockingaperture i 16 has a locking shoulder 19 and a shoulder 20 oppositethereto. Likewise, locking aperture 17 has a locking shoulder 21 and ashoulder 22 opposite thereto, and locking aperture 13 has a lockingshoulder 23 and a shoulder 24 opposite thereto. Also formed through thelid 11 recesses in the ends of the tumblers. The cam surface 47 of prong45 engages the cam surface 37 of recess 36 in tumbler 28, and thedownward movement of the key relative to the tumbler causes the tumbler28 to flex slightly to the right, to the position shown in FIG. 7, sothat the unlocking shoulder 32 on the tumbler clears the unlockingshoulder 21 of aperture 17. In' like manner, the cam surface 48 on keyprong 46 engages the cam surface 4-1 of tumbler 29 so that the tumbler29 is flexed slightly to the left, to the position shown in FIG. 7, sothat the unlocking shoulder 34 thereof clears the locking shoulder 23 ofaperture 18. In like manner, the tumbler 27 is moved to its unlockingposition by the unlocking prong 44 of key 14. When the key 14 has beenmoved downwardly as far as it goes, all of the tumblers 27, 28 and 29will be unlocked so that the lid may be opened. The key may be left inplace, if desired, as the lid is opened. a

After the lid has been opened, the key may be removed. The tumblers willnow return to their unflexed positions shown in FIGS. 2 and 4. In orderto allow the lid to close, the tumblers 27, 28 and 29 are provided withinclined cam surfaces 51, 52 and 53, respectively, for cooperation withthe locking shoulders 19, 21 and 23 of the locking apertures 16, 17 and18. For example, the locking shoulder 21 of aperture 17 will engage theinclined cam surface 51 of tumbler 28 causing the tumbler 28 to flexslightly to the right so that the tumbler may pass through the lockingaperture 17. When the lid is completely closed, the flexibility of thetumbler will cause it to snap over into hooked engagement with thelocking shoulder of the aperture so that the lid is again secured. Inlike manner, the other two tumblers 27 and 29 will be cammed to theirunlocking position as the lid is closed and they also will snap intohooked engagement with the locking shoulders of their respective lockingapertures when the lid is completely closed.

The tumblers 27, 2S and 29 are also designed so that they will notunlock if they are flexed beyond their unlocking position. As shown inFIG. 7, when the tumbler 28 is in its unlocking position, the lockingshoulder 61 thereon clears the shoulder 22 of the locking aperture 17 sothat the tumbler can pass through the locking aperture. However, if thetumbler 28 is flexed too far to the right, the locking shoulder 61 ofthe tumbler will engage the aperture shoulder 22 to prevent unlocking.This construction prevents accidental unlocking by merely pushing thetumbler all the way to its right, as might be done by a child. Thetumblers 27 and 29 are similarly formed for cooperation with theshoulders 20 and 24 of the locking apertures 16 and 18, respectively.

As may be seen from the foregoing description, an inexpensive lockingmechanism has been provided which will enable the box to be securelyfastened when the lid is closed but which will at the same time permiteasy access into the box by means of the key 14.

Although the tumblers have been shown in the drawings as being in aslightly staggered row when unfiexed, it is to be realized that thetumblers in their unfiexed position could all be in a row, aligned withone another. In such event, the locking apertures in recess would haveto be slightly rearranged so that the locking shoulders of the lockingapertures would underlie the locking shoulders of the tumblers when thetumblers are in their unfiexed position. If such a modification weremade, the unlocking and locking would take place in exactly the samemanner as previously described. Similarly, the locking apertures 16, 17and 18 could all be in a row, aligned with one another. In such anevent, the tumblers would have to be originally molded in a much morestaggered unfiexed relationship than shown, in order that the lockingshoulder of the tumblers would overlie the locking shoulder of theapertures when the tumblers are in their unfiexed positions. However,the principle of operation would remain the same.

It is also possible that the tumblers, which are shown in the figures asadjacent one another, could be slightly spaced apart. In this case,separated locking apertures could be provided. However, if the aperturesand tumblers are arranged in such manner that the tumblers, whenunfiexed, have the locking shoulders thereon overlying the lockingshoulders of the apertures and the apertures are of a width wider thanthe width of the tumbler, the principles of the present invention wouldstill be employed.

As an even further modification, the tumblers could be arranged in someother manner than in a row. For example, the tumblers could be arrangedin a generally circular manner with either individual locking aperturesbeing provided for each tumbler or merely one large aperture provided insuch manner that the locking shoulders of the tumblers would overlie theedge of the locking aperture. In order for the tumblers to be thenunlocked in the last instance, they could be moved to- 4. ward thecenter of the one large aperture, away from their hooked engagement withthe shoulder of the aperture.

Other configurations utilizing the principles of this invention willsuggest themselves. However, in any of these arrangements it isconsidered essential that at least two of the tumblers move in differentdirections in order to unlock the lid. There are at least two reasonsfor this requirement. One reason is that if all tumblers moved in thesame direction to unlock the lid, it would be quite easy for a smallchild to accidentally manipulate the tumblers in this direction to openthe lid, thereby defeating one of the main objects of the invention.Another reason for the different direction of movement of the tumblersto their unlocking position is that unlocking cannot occur because ofrelative sliding movement of the lid on the body of the box. As may beappreciated, one of the purposes of the present invention is to providelocking mechanisms for inexpensive, plastic containers, which containershave a relatively high degree of flexibility. If all of the tumblerswere movable in the same direction to their unlocking position, it wouldbe quite possible for the box to accidentally open by a sidewiseshifting movement of the lid relative to the body in the oppositedirection which would cause the unlocking shoulders of the tumblers andapertures to disengage. This, however, is prevented when the tumblershave to move in different directions to their unlocking positions. Thus,if the lid were shifted to unlock one tumbler, at least one othertumbler would still lock the lid closed.

Although the preferred embodiment of the invention which is illustratedherein is shown as having three tumblers, it is to be realized that theinvention is not limited to that precise embodiment, but that any numberof tumblers from two on up may be used as desired.

The present invention, as described, has been formed by injectionmolding of polypropylene. However, it is to be realized that othermaterials could be used for the formation of the locking mechanism, aslong as the tumblers have sufiicient flexibility to enable them to beflexed back and forth from their locking to their unlocking positions,in the manner as described herein.

Although the particular embodiment of the invention illustrated hereinhas been depicted as used with a box having a hinged lid, it is to berealized that the invention could be used with other types of doormembers. For example, the invention would find utility in a sliding doorarrangement, wherein the tumblers were carried on the sliding door andthe locking apertures were provided in the door frame. Naturally, theopposite arrangement could be made, if desired.

Still another change that could be made would be to bridge over the topof the recess to provide only a narrow slot for the insertion of the keyinto the recess. Such construction would be slightly more expensive, butit would increase the security of the locking mechanism since it wouldprevent entry of little fingers into the recess.

As may thus be appreciated, the embodiment of the invention describedherein is merely a preferred embodiment of the same, and various changesin the shape, size and arrangement of parts may be resorted to withoutdeparting from the spirit of the invention or the scope of the attachedclaims.

Having thus described my invention, what I claim and deisre to secure byLetters Patent is:

1. Locking mechanism for locking two members when closed, comprising:

one of said members having a plurality of locking aperturestherethrough, said locking apertures each having a locking shoulder andanother shoulder opposite thereto;

a plurality of flexible tumblers on the other of said members, saidother of said members and said tumblers thereon comprising an integrallymolded plastic member, each tumbler being associated and in alignmentwith one of said locking apertures, each tumbler having a portionthereof projecting through its associated locking aperture when saidmembers are closed, which portion has a locking shoulder thereonnormally hooking over the locking shoulder of the locking aperture whensaid tumblers are unflexed, the tumbler portions each having an over-allwidth less than the distance between the opposed shoulders of theassociated locking aperture, said tumblers each being flexible to anunlocking position wherein the locking shoulders of said tumbler andlocking aperture are out of hooked engagement, said locking aperturesand tumblers being arranged so that at least two of said tumblers flexin different directions to their unlocking positions;

interengageable cam surfaces on said tumblers and said one member forflexing said tumblers to their unlocking positions as said members areclosed together to enable said tumbler portions to pass through saidlocking apertures.

2. Locking mechanism for locking two members together, comprising:

one of said members having a plurality of locking aperturestherethrough, said locking apertures each having a locking shoulder andanother shoulder opposite thereto;

a plurality of flexible tumblers on the other of said members, eachtumbler being associated and in alignment with one of sad lockingapertures, each tumbler having a portion thereof projecting through itsassociated locking aperture when said members are closed, which portionhas a locking shoulder thereon normally hooking over the lockingshoulder of the locking aperture when said tumblers are unflexed, thetumbler portions each having an over-all width less than the distancebetween the opposed shoulders of the associated locking aperture, saidtumblers each being flexible to an unlocking position wherein thelocking shoulders of said tumbler and locking aperture are out of hookedengagement, said locking apertures and tumblers being arranged so thatat least two of said tumblers flex in different directions to theirunlocking positions;

a key, interengageable cam means on said key and tumblers for flexingall of said tumblers simultaneously to their unlocking positions.

3. In a locking mechanism as set forth in claim 2 and further includinginterengageable cam surfaces on said tumblers and said one member forflexing said tumblers to their unlocking positions as said members areclosed together to enable said tumbler portions to pass through saidlocking apertures.

4. In a locking mechanism as set forth in claim 2 wherein saidinterengageable cam means on said key and tumblers for flexing saidtumblers to their unlocking positionscomprises said tumbler portionshaving a recess formed thereinto from the end of said tumbler portions,said key having unlocking prongs insertable into the recesses of saidtumbler portions, said unlocking prongs and said tumbler portionrecesses having interengageable cam surfaces for moving said tumblers totheir unlocking positions as said unlocking prongs are inserted intosaid tumbler portion recesses.

5. Locking mechanism as set forth in claim 4 wherein said other of saidmembers and the tumblers thereon comprise an integrally molded plasticmember.

6. Locking mechanism for locking two members together, comprising:

one of said members having a plurality of aligning aper tures andlocking apertures therethrough, said locking apertures each having alocking shoulder and another shoulder opposite thereto;

a plurality of tumblers on the other of said members, each tumbler beingassociated and in alignment With one of said locking apertures, eachtumbler having a portion thereof projecting through its associatedlocking aperture when said members are closed, which portion has alocking shoulder thereon normally hooking over the locking shoulder ofthe locking aperture, the tumbler portions each having an overall Widthless than the distance between the opposed shoulders of the associatedlocking aperture, said tumblers each having a flexible neck to permitflexing of said tumbler portions to an unlocking position wherein thelocking shoulders of said tumbler and locking aperture are out of hookedengagement, said locking apertures and tumblers being arranged so thatat least two of said tumbler portions flex in different directions totheir unlocking positions;

a key having alignment prongs insertable into said alignment apertures,interengageable cam means on said key and tumbler for flexing all ofsaid tumbler portions to their unlocking positions when said alignmentprongs on said key are inserted into said alignment prongs; and

interengageable cam means on said tumbler portions and said one memberfor flexing said tumbler portions to their unlocking positons as saidmembers are closed together to enable said tumbler portions to passthrough said locking apertures.

7. Locking mechanism for locking two members together, comprising:

one of said members having a recess therein and a plurality of lockingapertures therethrough within said recess, said locking apertures eachhaving a locking shoulder and another shoulder opposite thereto;

a plurality of flexible tumblers on the other of said members, eachtumbler being associated and in alignment with one of said lockingapertures, each tumbler having a portion thereof projecting through itsassociated locking aperture into and completely within said recess whensaid members are closed, which portion has a locking shoulder thereonnormally hooking over the locking shoulder of the locking aperture whensaid tumblers are unflexed, the tumbler portions each having an over-allwidth less than the distance between the opposed shoulders of theassociated locking aperture, said tumblers each being flexible to anunlocking position wherein the locking shoulders of said tumbler andlocking aperture are out of hooked engagement, said locking aperturesand tumblers being arranged so that at least two of said tumblers flexin different directions to their unlocking positions;

a key, interengageable cam means on said key and tumblers for flexingall of said tumblers simultaneously to their unlocking positions;

interengageable cam surfaces on said tumblers and said one member forflexing said tumblers to their unlocking positions as said members areclosed together to enable said tumbler portions to pass through saidlocking apertures.

8. Locking mechanism for locking two members together, comprising:

one of said members having a recess therein and a plurality of lockingapertures therethrough within said recess, said locking apertures eachhaving a locking shoulder and a shoulder opposite thereto, said onemember having a plurality of aligning apertures therethrough;

a plurality of tumblers on the other of said members, each tumbler beingassociated and in alignment with one of said locking apertures, eachtumbler having a portion thereof projecting through its associatedlocking aperture into and completely within said recess when saidmembers are closed, which portion has a locking shoulder thereonnormally hooking over the locking shoulder of the locking aperture, thetumbler portions each having an over-all width less than the distancebetween the opposed shoulders of the associated locking aperture, saidtumblers each having a flexible neck to permit flexing of said tumblerportions to an unlocking position wherein the locking shoulders of saidtumbler and locking aperture are out of hooked engagement, said lockingapertures and tumblers being arranged so that at least tWo of saidtumbler portions flex in different directions to their unlockingpositions;

a key having alignment prongs insertable into said alignment apertures,interengageable cam means on said key and tumbler for flexing all ofsaid tumbler portions to their unlocking positions when said alignmentprongs on said key are inserted into said alignment prongs; and

interengageable cam means on said tumbler portions and said one memberfor flexing said tumbler portions to their unlocking positions as saidmembers are closed together to enable said tumbler portions to passthrough said locking apertures.

9. In a locking mechanism as set forth in claim 8 wherein saidinterengageable cam means on said key and tumblers for flexing saidtumblers to their unlocking positions comprises said tumbler portionshaving a recess formed thereinto from the end of said tumbler portions,said key having unlocking prongs insertable into the recesses of saidtumbler portions, said unlocking prongs and said tumbler portionrecesses having interengageable cam surfaces for moving said tumblers totheir unlocking positions as said unlocking prongs are inserted intosaid tum bler portion recesses.

References Cited in the file of this patent UNITED STATES PATENTS406,173 Lipe July 2, 1889 571,169 McCartney Nov. 10, 1896 2,906,579Magnenat Sept. 29, 1959

2. LOCKING MECHANISM FOR LOCKING TWO MEMBERS TOGETHER, COMPRISING: ONE OF SAID MEMBERS HAVING A PLURALITY OF LOCKING APERTURES THERETHROUGH, SAID LOCKING APERTURES EACH HAVING A LOCKING SHOULDER AND ANOTHER SHOULDER OPPOSITE THERETO; A PLURALITY OF FLEXIBLE TUMBLERS ON THE OTHER OF SAID MEMBERS, EACH TUMBLER BEING ASSOCIATED AND IN ALIGNMENT WITH ONE OF SAD LOCKING APERTURES, EACH TUMBLER HAVING A PORTION THEREOF PROJECTING THROUGH ITS ASSOCIATED LOCKING APERTURE WHEN SAID MEMBERS ARE CLOSED, WHICH PORTION HAS A LOCKING SHOULDER THEREON NORMALLY HOOKING OVER THE LOCKING SHOULDER OF THE LOCKING APERTURE WHEN SAID TUMBLERS ARE UNFLEXED, THE TUMBLER PORTIONS EACH HAVING AN OVER-ALL WIDTH LESS THAN THE DISTANCE BETWEEN THE OPPOSED SHOULDERS OF THE ASSOCIATED LOCKING APERTURE, SAID TUMBLERS EACH 